Trying again for a baby panda

The National Zoo’s giant panda Mei Xiang lost a cub in September after its liver failed

View Photos

.

Caption

Liver failure caused by an insufficient supply of oxygen caused the death of the giant panda cub last month at the National Zoo.

Oct. 11, 2012Mei Xiang, the female giant panda that lost its baby last month, takes a nap after being fed a frozen fruit treat at the National Zoo. Chief veterinarian Suzan Murray said a necropsy showed the tiny cub’s lungs were not fully formed. That impeded the flow of oxygen, leading to liver necrosis, or the death of liver cells.Astrid Riecken/For The Washington Post

After determining “no competent breeding” had occurred between Giant Pandas Mei Xiang and Tian Tian on Friday , despite the two having been left alone together for a couple hours, scientists and veterinarians at the Smithsonian National Zoo moved quickly Saturday morning to artificially inseminate the female, Mei Xiang.

Pandas are able to breed once a year for a few days. And Mei Xiang and Tian Tian have never been successful breeding naturally, said Zoo spokesman Pamela Baker-Masson. Their only living offspring, Tai Shan, who was born in 2005 and nicknamed Butterstick, was the product of human intervention, and since then scientists and veterinarians have inseminated Mei Xiang five times without success.

The artificial semination that took place Saturday was the first attempt to impregnate Mei Xiang since the death of her cub last year.

Mei Xiang — and Tian Tian — stunned the public and their caretakers in September when Mei Xiang unexpectedly gave birth. Pregnancy can be hard to spot in Giant Pandas.

Six days after the surprise birth, jubilation dissolved into grief when distress calls by Mei Xiang alerted veterinarians to the cub’s lifeless body.

This year’s panda pregnancy watch began Tuesday, when zoo veterinarians noticed elevated estrogen levels in Mei Xiang. To enable breeding, they closed the Giant Panda habitat to visitors to cut down on noise and other distractions, and left the pair alone together Friday evening. When that didn’t work out as hoped, Mei Xiang was put under general anesthesia Saturday morning and inseminated using a combination of fresh and frozen sperm from Tian Tian, zoo officials said.

“They were put together for a couple of hours last evening,” said Baker-Masson. “No successful breeding took place. They were separated.”The procedure was performed by Tang Chunxiang, the assistant director and chief veterinarian of the China Conservation and Research Center for the Giant Panda at Wolong. A second insemination attempt was possible Saturday evening, Baker-Masson said.

The next step is familiar by now: watch and wait.

“We are hopeful that our breeding efforts will be successful this year, and we’re encouraged by all the behaviors and hormonal data we’ve seen so far,” said Dave Wildt, head of the Center for Species Survival at the Smithsonian Conservation Biology Institute. “We have an extremely small window of opportunity to perform the procedures, which is why we monitor behavior and hormones so closely.”

Female Giant Pandas can produce offspring as late as their early 20s, but most stop in their late teens, Baker-Masson said. Mei Xiang turns 15 in July and Tian Tian turns 16 in August. They are at the zoo under a $10 million agreement with China that lasts until 2015, to try to help stave off extinction for the estimated 1,600 Giant Pandas left in the world.

The popular Panda Cam, which allows the public to observe the animals in their enclosure day and night, was turned off Saturday morning during the procedure.

Giant Panda fanatics might have recognized that as a sign to stay away, but many visitors to the zoo Saturday were unprepared to see a blue sign that read: “Panda House Is Closed.”